ITU Speech Codecs on TI C64x™ Processor

Ittiam offers the complete suite of ITU speech codecs for IP Telephony applications on Texas Instruments' C64x™ processor. These implementations are based on Ittiam's portable and optimized C model and have been handcrafted for high performance with low resource utilization (CPU cycles, memory and interrupt latency).

Ittiam's speech codec implementations on the TI C64x™ are targeted at a wide variety of end equipment, ranging from single channel products (like IP Phones, Video Phones, Internet Access Devices) to high density applications (voice/trunking gateways).

The ITU speech codecs available on the TI C64x™ platform include the G.711, G.726, G.728, G.729AB, G.723.1A, G.722 and G.722.1 codecs.

The speech codecs are complemented by other VoIP and Telephony functions also available on the TI C64x™ platform. These functions include a G.168-2000 compliant Line Echo Canceller (LEC), DTMF and Call Progress Tones (CPT) generation and detection, Caller Identification (Caller-ID), VAD/DTX/CNG, Fax/Data/Voice (FDV) Call Discrimination, Packet Loss Concealment (PLC) and Acoustic Echo Cancellation (AEC).

High Performance

Ittiam's speech codecs on the TI C64x™ are optimized to take full advantage of the VLIW and SIMD capabilities of the processor. Compute intensive segments of the codecs are hand-crafted in assembly to achieve the low MCPS, low memory usage and low interrupt latency.

Resource utilization for Ittiam's G.723.1A codec (encoder and decoder) implementation on TI's C64x™ is shown as example. On a 500 Mhz C64x™ CPU, less than 1.5% of the CPU power is used for encoding and decoding of G.723.1.

Ittiam's optimized speech codec solutions provide unparalleled channel densities for high capacity, server class applications.

Efficient Memory Management

Ittiam speech codec implementations use scratch memory as a working area during execution and use persistent memory to store state information. Persistent, Scratch and Table data spaces are dynamically relocatable. This approach avoids fragmentation, minimizes system stack usage and enables efficient use of memory for multiple channels/algorithms

Re-entrant, Multi-channel implementation

Ittiam speech codec implementations are interruptible and re-entrant and can be used in multi-channel, multi-functional systems. The implementations support relocatable program and data spaces.

Standard Interface

Ittiam's speech codec implementations on the TI C64x™ support a uniform C callable interface suitable for use in any framework or operating environment. The implementations are also compliant to TI eXpressDSP™ (XDAIS) standards

Summary of features

• Bit-exact fixed-point implementation per ITU-T test suite
• Highly optimized implementations with low MCPS and memory usage offering unparalleled channel densities
• Efficient memory management that minimizes load on system-stack
• Reentrant, interruptible, multi channel implementation
• TI eXpressDSP™ compliant algorithms

For more information, contact mkt@ittiam.com